This invention relates to the general field of ventilation and dust separation, and particularly to ventilation equipment adapted for use in military armored vehicles. Such vehicles have historically presented some of the most difficult applications for dust separators and air cleaners. The problems result from the limited space available and the heavy dust concentrations frequently encountered by tracked armored vehicles. Dust concentrations outside the vehicle as high as twenty times zero visibility, that is, up to 0.5 grams per cubic foot of air, have been encountered. The vehicles are by no means hermetically sealed, and dust concentrations within the vehicles often can exceed zero visibility, defined as 0.025 grams per cubic foot of air. This dust can permeate communications equipment, gun breech mechanisms, optical instruments, turret bearings, and electronic equipment of all types. The result of such dust permeation is often premature equipment failure. Visibility within the vehicle is also impaired, and the crew members are often forced to wear masks to avoid inhaling the dust.
Most armored vehicles utilize crew compartment ventilation blowers, designed to provide ventilation air for the crew members and to assist in the removal of gun fumes. These blowers are air movers only, and in many cases act as dust pumps to accelerate the entry of dust into the vehicle.